Conventionally, in the field of photo-sensitive materials or magnetic recording media etc., a coating process for forming a coating film in that a predetermined coating liquid is applied onto a continuously conveyed band-like flexible support body (hereinafter, referred to as “web”) has been employed. Recently, in these fields, a coating technology is required which can provide a coating film having a film thickness of high accuracy and a surface that is flat and has no coating irregularity.
Similarly, also in a coating process applied to production of an optical film having various functionalities such as an optical compensation film, antireflection film or antidazzle film, the coating technology above is necessary.
Conventionally, it has been circumstances that a coating device for applying a coating liquid onto the surface of a web includes, for example a type of a roll coater, gravure coat, roll coat with a doctor, reverse roll coater, extrusion, or slide coat, and different coating device is used depending on its application.
In any of these coating devices, in order to achieve a coating film having a film thickness of high accuracy and a flat surface without coating irregularity, it is important to eliminate vibration at coating. For this purpose, a big separate foundation is usually provided on a base level (normally, the first floor in a building) and the coating device, generally, is established on the foundation. According to this, vibration of the foundation itself is suppressed to protect a coating film from being badly affected.
However, in such method, it is requested in principle to establish a coating device on a base level, and so there are disadvantages that the establishment is very expensive and constraints are posed on design and layout.
In order to resolve these problems, it is proposed that a reverse roll coating device is provided with a vibration suppression portion to damp vibration acting on a web (see, Patent Document 1). Also, it is proposed that at least one drive system is mounted on a vibration isolation system when coating a cylindrical base material (see, Patent Document 2).
Patent Document 1: Japanese Patent Application Laid-Open No. 2002-239432
Patent Document 2: Japanese Patent Application Laid-Open No. 9-206660